}

// Returns a vector of passes from their names. If a pass is not found, then the
// corresponding return entry is null.
static std::vector<GraphOptimizationPass*> FindRegisteredPassesByName(
    const std::vector<std::string>& pass_names) {
  std::vector<GraphOptimizationPass*> pass_ids(pass_names.size(), nullptr);

  for (const auto& group : OptimizationPassRegistry::Global()->groups()) {